Topic Summary

Posted by: Admin

lower values is better.use work size 64, work size is how much separate "threads/processes" run simultaneously, it doesn't directly related to performance, different devices have different optimum value. 512 doesn't mean better 64.

Posted by: ektorbarajas

Posted by: Admin

Thanks for reminder, we fixed help text:Don’t turn on OpenCL acceleration if the results of OpenCL benchmark are longer in ms. than processor’s benchmark, because this will increase overhead costs due to increased expenses for data transfer to the OpenCL device.

Posted by: ektorbarajas

So the rule of thumb is that if a benchmark throws the OpenCL speed lower than 1 CPU cure, then OpenCL should be used?

For example:

CPU Speed (1 Core): 281msOpenCL Device Speed: 78ms

menas that there is a real benefit enabilg OpenCL

While

CPU Speed (1 Core): 581msOpenCL Device Speed: 754ms

means that OpenCL MUST NOT BE enabled?

Then indeed the help statement is wrong:"Don’t turn on OpenCL acceleration if the results of OpenCL benchmark are lower than processor’s benchmark, because this will increase overhead costs due to increased expenses for data transfer to the OpenCL device. "

Regards

Posted by: Admin

Benchmarking doesn't count transfer time, it only shows pure math power. In your situation your OpenCL more powerful when your CPUs you can enable it.Work size hasn't simple best value, try use different values and benchmark, some video cards hast best values in 128 some in 64.

Posted by: ektorbarajas

I noticed that when running an OpenCL benchmark, the results are expressed in speed (ms) for example:

CPU Speed (1 Core): 281msOpenCL Device Speed: 78ms

According to this, then OpenCL must be enabled since openCL is faster than 1 CPU Core,

BUT the online help says the opposite:"Don’t turn on OpenCL acceleration if the results of OpenCL benchmark are lower than processor’s benchmark, because this will increase overhead costs due to increased expenses for data transfer to the OpenCL device. "